The disclosure relates to electronic signal processing. More particularly, the disclosure relates to an RF receiver and receiver architecture.
In a typical frequency division multiplex communication system, multiple transmissions can simultaneously occupy a predefined operating band. The signals within the operating band can operate according to a predetermined communication standard, and thus, can have an energy within a predictable dynamic range. The communication standard can also specify a frequency spacing between adjacent channels, and the channel bandwidth. The communication standard can also specify signal parameters, such as modulation type, information rates, out of channel performance, as well as other signal parameters.
Additionally, there can be numerous signal sources operating outside of the operating band. Unlike the signals within the operating band, the out of band signals are typically not regulated by the communication standard regulating the in band signal performance. As a result, out of band signals may have substantially greater energy relative to the in-band signals, and can operate according to different signal parameters, including modulation type, out of band performance, and other parameters.
In order to tune to a desired channel, a receiver needs to substantially eliminate the effects of undesired channels, including those known interferers occurring within known operating bands as well as unanticipated interferers.
Many receiver implementations have been developed to support the various communication standards. The trend of increasing device complexity and performance while simultaneously reducing the physical size of electronic devices imposes tremendous constraints on ongoing development.
For example, the size of cellular and cordless telephones continues to shrink while simultaneously improving the quality of the device and adding additional functionality to the device. Similarly, radios and televisions are constantly being redesigned to provide improved features and operating modes while simultaneously decreasing physical size. Although the screen size available in television receivers continues to grow, the advancement of technologies that enable flat screens and short depths greatly reduce the volume available for electronics.
It is desirable to increase the ability of a receiver to operate in multiple modes or frequency bands without compromising received signal quality. Additionally, it is desirable for a receiver implementation to minimize size, cost, and power consumption over implementations presently available.